This invention relates generally to pedals for use on bicycles and the like, and, more particularly, to clipless pedals configured to releasably secure cleats attached to a rider""s shoes.
Clipless pedals of this particular kind typically include forward and rearward cleat retainers mounted on the pedal""s upper surface. One or both of these cleat retainers are configured to be forceably retractable apart from each other, to receive and releasably secure forward and rearward projections that are part of a cleat attached to the sole of a rider""s shoe. The rider can release the cleat and shoe from the pedal simply by rotating the shoe by a predetermined amount about an axis perpendicular to the pedal""s upper surface.
These clipless pedals typically further include a main body that is mounted for rotation on a spindle, with forward and rearward recesses being defined in the main body, on opposite sides of the spindle. Pivot rods are disposed within these recesses, generally parallel with the spindle, for supporting the forward and rearward cleat retainers. Each cleat retainer can include a coil wrapped around the associated rod and can further include an inverted U-shaped loop that projects upwardly from the coil to a position for engagement by a cleat projection. The coils function to yieldably resist pivoting movement of the two loops apart from each other.
Alternatively, the cleat retainers can incorporate similar U-shaped projections whose movement apart from each other is yieldably resisted by an elastomeric material. The cleat retainers can be formed of any suitable material, including stamped sheet metal, forged metal, or wire.
To release the shoe""s securement to the pedal, the rider simply rotates the shoe by a predetermined amount, e.g, 15-20xc2x0, about an axis perpendicular to the pedal""s upper surface. This causes laterally extending arms on the cleat to engage the forward and rearward cleat retainers and forceably urge the cleat retainers apart from each other, to release their retention of the cleat.
Optionally, the clipless pedals of the kind described briefly above can be configured as two-sided pedals, in which a second set of forward and rearward cleat retainers, identical to the first set, is located on the opposite side of the pedal""s main body. This allows the pedal to secure the rider""s shoe in either of two orientations. The forward cleat retainer of the first set can be integrated with the rearward cleat retainer of the second set; likewise, the rearward cleat retainer of the first set can be integrated with the forward cleat retainer of the second set.
The clipless pedals of the kind described briefly above have proven to be effective in providing a secure attachment of the rider""s shoe, while at the same time allowing for a convenient and reliable release of the shoe. However, the pedals are not believed to be configured for effective operation in all circumstances. In certain riding conditions, the pedal can undesirably release its securement of the shoe.
More particularly, when the rider pulls upwardly on the pedal, the rider""s ankle automatically will tend to pivot downwardly such that the upward force is applied to the pedal in a direction that includes a vector component toward the pedal""s rear. This rearward force component is resisted by the rearward cleat retainer. However, if the rearward force is particularly strong, as for example when the rider accelerates from a stop, it can retract the rearward cleat retainer sufficiently to allow the cleat""s front projection to escape from its retention by the forward cleat retainer, thereby releasing the cleat from the pedal. This, of course, is highly undesirable, and it can lead to a serious injury of the rider.
It should, therefore, be appreciated that there is a need for an improved clipless pedal of the kind that incorporates forward and rearward cleat retainers, which provides a reliable securement of a rider""s shoe in substantially all riding conditions, including a rapid acceleration. The present invention satisfies this need and provides further related advantages.
The present invention is embodied in a clipless pedal configured to releasably secure a cleat attached to a rider""s shoe in substantially all riding conditions. The pedal includes a main body mounted for rotation on a spindle and having an upper face configured for engagement with the cleat of a rider""s shoe. Forward and rearward cleat retainers project upwardly from the upper face of the main body, on opposite sides of the spindle. These cleat retainers are sized and configured to be forceably retractable in forward and rearward directions apart from each other, so as to receive and retain forward and rearward projections that are part of the cleat, to secure the rider""s shoe to the pedal. The cleat retainers are configured to be engaged by disengagement cams that are part of the cleat, to forceably retract the forward cleat retainer in a forward direction and the rearward cleat retainer in a rearward direction when the cleat is rotated about an axis generally perpendicular to the upper face of the main body. This releases the cleat and the rider""s shoe from the pedal. Further, the upper face of the main body defines a forward wall located beneath the forward cleat retainer and a rearward wall located beneath the rearward cleat retainer. These walls are configured to prevent the cleat from moving non-rotationally in a forward or rearward direction relative to the pedal, by an amount sufficient to overcome the yielding bias of the forward or rearward cleat retainer and release the cleat from the pedal.
In a more detailed feature of the invention, the forward and rearward walls can be defined by a wall/stop fixture secured to the main body or they can be integrated as part of the main body. The wall/stop fixture can be formed as a one-piece or multi-piece component, and it can include forward and rearward arms that are positioned to engage the respective forward and rearward cleat retainers, to prevent the cleat retainers from moving closer to each other than a predetermined minimum distance.
In other more detailed features of the invention, the main body has a generally rectangular shape, and the cleat retainers are disposed within forward and rearward recesses, located on opposite sides of the spindle. Pivot rods are disposed within the respective forward and rearward recesses, oriented generally parallel with the spindle. The forward cleat retainer includes a coil wrapped around the forward pivot rod and an inverted U-shaped loop that projects upwardly from the coil to a position for engagement by the forward projection of the cleat, such that forward movement of the loop is yieldably resisted by the coil. Similarly, the rearward cleat retainer includes a coil wrapped around the rearward pivot rod and an inverted U-shaped loop that projects upwardly from the coil to a position for engagement by the rearward projection of the cleat, such that rearward movement of the loop is yieldably resisted by the coil.
In yet other more detailed features of the invention, the forward and rearward cleat retainers each include an inverted U-shaped loop having two upright legs and a cross bar. The inverted loops are positioned to be engaged by disengagement cams formed in the corners of the cleat when the cleat is rotated by a predetermined amount. This engagement forceably retracts the forward cleat retainer in a forward direction and the rearward cleat retainer in a rearward direction, to release the cleat and the rider""s shoe from the pedal. The forward wall of the wall/stop fixture is located beneath and immediately forward of the cross bar of the forward U-shaped loop, between the loop""s upright legs. Similarly, the rearward wall of the wall/stop fixture is located beneath and immediately rearward of the cross bar of the rearward U-shaped loop, between the loop""s upright legs. The forward and rearward walls both can be arcuate, so as to limit forward and rearward movement of the cleat relative to the pedal over a range of angular orientations.
The pedal of the invention optionally can be configured to be two-sided, with the main body further having a lower face, opposite the upper face, also configured for engagement with the cleat of a rider""s shoe. In such case, a second set of forward and rearward cleat retainers is provided, substantially identical to the first set of forward and rearward cleat retainers, but projecting downwardly from the lower face of the main body. The lower face of the main body defines forward and rearward walls, substantially identical to the walls on the pedal""s upper face. These walls, which can be defined by a wall/stop fixture, are configured to prevent the cleat from moving non-rotationally in a forward or rearward direction relative to the pedal, by an amount sufficient to overcome the yielding bias of the forward or rearward cleat retainer and release the cleat from the pedal. The forward cleat retainer of the first set can be integrated with the rearward cleat retainer of the second set, and the forward cleat retainer of the second set can be integrated with the rearward cleat retainer of the first set.
Another aspect of the invention resides in a method for assembling the pedal. Specifically, the method includes a step of placing the forward and rearward cleat retainers in their positions on the pivot rods in the respective forward and rearward recesses, while the retainers are in an unstressed condition. The cleat retainers then are forceably retracted apart from each other, and the wall/stop fixture defining the forward and rearward walls is secured to the main body. Finally, the cleat retainers are released, such that they move back toward each other and into contact with the respective forward and rearward arms of the wall/stop fixture.
Other features and advantages of the present invention should become apparent from the following description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.